I accidentally had some experiences while doing yoga, this book clarified the experience that I had. Many books are too subtle that it doesn't clarify or too dense that it is hard to grasp. This was just perfect.

I actually want to have quiz and exam on this book so that I don't forget the wonderful information in this book. Most importantly, this book gave me the theorectical reasons behind some of the yoga practices that we do.

Mind blown that this author who is English I think (certainly not Indian) not only seems to have proficiency in Sanskrit and Tamil, but have also written books in Tamil.

This book is a marvel. The title is perfect, it is "essential" indeed.